Search results
Results from the WOW.Com Content Network
The Mach number (M or Ma), often only Mach, (/ m ɑː k /; German:) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. [1] [2] It is named after the Austrian physicist and philosopher Ernst Mach. =, where: M is the local Mach number,
Dimensionless numbers (or characteristic numbers) have an important role in analyzing the behavior of fluids and their flow as well as in other transport phenomena. [1] They include the Reynolds and the Mach numbers, which describe as ratios the relative magnitude of fluid and physical system characteristics, such as density, viscosity, speed of sound, and flow speed.
More than 99 percent of all species, amounting to over five billion species, [7] that ever lived on Earth are estimated to be extinct. [8] [9] Estimates on the number of Earth's current species range from 10 million to 14 million, [10] of which about 1.2 million have been documented and over 86 percent have not yet been described. [11]
It is the fastest mammal in the world and one of the fastest flying animals on level flight. Cheetah: 109.4–120.7 km/h (68.0–75.0 mph) [d] The cheetah can accelerate from 0 to 96.6 km/h (60.0 mph) in under three seconds, [58] though endurance is limited: most cheetahs run for only 60 seconds at a time. [19]
The subsonic speed range is that range of speeds within which, all of the airflow over an aircraft is less than Mach 1. The critical Mach number (Mcrit) is lowest free stream Mach number at which airflow over any part of the aircraft first reaches Mach 1. So the subsonic speed range includes all speeds that are less than Mcrit.
Few insects are as beloved as the monarch butterfly. These fascinating creatures are beautiful, boldly colored and surprisingly strong — the North American monarch migrating thousands of miles ...
The Knudsen number is a dimensionless number defined as =, where = mean free path [L 1], = representative physical length scale [L 1].. The representative length scale considered, , may correspond to various physical traits of a system, but most commonly relates to a gap length over which thermal transport or mass transport occurs through a gas phase.
The male humpback whale that traveled the longest documented distance to date is observed in Zanzibar Channel, off the village of Fumba on the Tanzanian island of Unguja, on August 22, 2022.